Other approaches have been tried for authenticating consumables in a host, but none of these have proven satisfactory. In particular, the background approaches discussed below do not provide an effective anti-piracy deterrent. These previously known approaches do not provide adequate authentication and can often be defeated by copying, spoofing, or similar techniques.
One early technique to authenticate consumables relied on keyed shapes of the consumable. Such keyed shapes can be designed so that only a consumable in the keyed shape will fit into a given type of host. As one example, a particular brand of razor can be adapted to receive only razor blades having a particular keyed shape. As a second example, an ink jet printer can be adapted to receive only refill ink cartridges having a particular keyed shape. The use of such a keyed shape can prevent interchange of consumables between different types of host. That approach is generally ineffective for anti-piracy, however, because the keyed shape of the consumable can be readily observed and easily duplicated.
Also unsatisfactory are the “challenge and response” authentication algorithms used in transponders intended for automobile security systems, such as the Atmel TK556, and equivalents. Automotive security systems were designed for “one lock, few keys” applications, where a single secret number is programmed into each key and each lock. If a host device, such as a printer or a camera, is the “lock,” then such challenge-response transponders require that all the keys (media) and locks (printers) be programmed with the same secret number.
It is known to provide encodements on consumables, such as film units and/or hosts such as cameras, for identification purposes and to convey information about the film unit or camera. The term “encodement” very broadly describes a feature of physical media used to communicate one or more pieces of information to a machine. “Encodement” includes alphanumeric text and other indicia, symbols, and the like. An encodement can be detectable by various means, including but not limited to optical, magnetic, and/or punch readers.
U.S. Pat. No. 6,106,166 discloses a device having a transponder and a transceiver. An electrically or electronically programmable read/write memory contained in the transponder is integrally attached to a consumable. The transponder is capable of receiving a first RF frequency electromagnetic field and deriving power and address information therefrom, and then generating a second RF frequency electromagnetic field in response. The second electromagnetic field is characteristic of the data stored in memory. A transceiver is disposed within the host with an antenna and support components for polling each transponder. As instructed by a control logic processor, the transceiver can read manufacturing data from the transponder and write usage and processing data to the transponder for storage in memory.
Radio-frequency identification transponders are widely available in a variety of forms. One form, referred to as “inlay transponders” are identification transponders that have a substantially flat shape. The antenna for an inlay transponder is in the form of a conductive trace deposited on a non-conductive support. The antenna may have the shape of a flat coil and the like. Leads for the antenna are also deposited, with non-conductive layers interposed as necessary. Memory components, RF communications, and any control functions are provided by a chip mounted on the support and operatively connected through the leads to the antenna. Inlay transponders have been used as layers of identification tags and labels to provide encodements that are accessible at a distance. A camera having a radio-frequency identification transponder that can be accessed for writing and reading at a distance is disclosed in U.S. Pat. No. 6,173,119.
Another known type of transponder is a radio frequency identification (RFID) transponder. An RFID transponder can typically include a unique identifier installed by the manufacturer in non-volatile memory.
With respect to host devices, it is known to provide a consumable article, such as a print cartridge, with a transponder. The host device, such as a printer into which the cartridge is installed, includes a transceiver for detecting the type of media on the print cartridge. A transceiver and transponder of this general type are disclosed in U.S. Pat. No. 6,099,178 to Spurr et al. The Spurr patent discloses a printer adapted to sense the type of media installed and includes a radio frequency transceiver for transmitting a first electromagnetic field, and for sensing a second electromagnetic field. However, Spurr does not teach or suggest a means for authenticating the media bearing the transponder. The information encoded in the transponder in Spurr can be easily forged, thus rendering the system ineffective as an anti-piracy measure.
International Publication Number WO 98/52762 discloses an inkjet printer that uses an RFID tag for identifying the type of paper that is loaded in an inkjet printer. That approach offers contactless communication with a read/write memory that is added to the inkjet roll. That publication, however, does not teach or suggest an authentication method and apparatus in accord with this disclosure.
A need exists, therefore, for an effective anti-piracy measure using a transponder and transceiver for sensing information encoded on a consumable article for use in a host device, such as media for use in a printer.